Journal of Applied Physiology, Vol 51, Issue 1 143-147, Copyright © 1981 by American Physiological Society
Effects of airway occlusion at functional residual capacity in pentobarbital-anesthetized kittens
T. Trippenbach, R. Zinman and R. Mozes
The effects or airway occlusion at the end of inspiration on timing
parameters and the "integrated" phrenic activity were studied in 1- to
21-day-old kittens at two levels of pentobarbital anesthesia before and
after bilateral vagotomy. In intact kittens during the first 2 wk of life,
instead of the classical effects of airway occlusion at functional residual
capacity (FRC), shortening of both inspiration and expiration, a decrease
in amplitude and rate of rise of the integrated phrenic activity, or
augmented breaths were recorded. These effects were not altered by an
additional dose of pentobarbital sodium. In kittens of all ages, airway
occlusion performed after bilateral vagotomy had no significant effects on
either timing and phrenic activity. Therefore, vagally mediated reflexes
are probably responsible for the paradoxical effects of airway occlusion at
FRC. However, a possible contribution of the chest wall receptors cannot be
excluded.
